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Biomedical subjects

H C Lou

Publications and source records attributed to H C Lou.

At least 91 records · Page 5Linked to original sources
PubMed1978

Decreased cerebral blood flow after administration of sodium bicarbonate in the distressed newborn infant.

In the course of our studies on cerebral blood flow in newborn infants, we have observed a striking depressing effect of sodium bicarbonate infusion on cerebral blood flow which in some cases may severely aggravate cerebral ischemia. We measured cerebral blood flow before and after the treatment with 1 to 8 meqs of sodium bicarbonate in seven distressed newborn infants. The 133 Xe clearance technique was used. The results showed in six of the seven cases a decrease in cerebral blood flow, which in most cases was reduced to 14 to 22 ml/100 g/min, which is about half the value prior to the bicarbonate infusion. In one case an extreme reduction occurred: cerebral blood flow was reduced to 3 ml/100 g/min, well below the level compatible with tissue survival. The results are discussed with regard to the optimal treatment of the acidotic newborn.

Bicarbonates↗
PubMed1977

Aphasia and epilepsy in childhood.

The syndrome of progressive aphasia and epilepsy in childhood is delineated. Four cases are presented, three of which show the typical gradual onset, fluctuating course and EEG changes with bilateral foci of spike and spike-wave activity, and, finally, normalization after some years of the EEG. Also the aphasia tends to subside, but often with considerable delay in relation to the other features. Neuropsychological assessment showed varying residual defects mainly on language functions. The aetiology is unknown. No pathoanatomical data on this disorder has hitherto been published. In one of the present cases a cortical biopsy was performed on suspicion of a left temporal tumour. The biopsy showed changes indicative of a slow virus infection. It is therefore suggested that the newly established language function in children particularly is vulnerable to a subchronic viral encephalitis affecting both hemispheres.

Adolescent↗
PubMed1977

Platelet hyperaggregability in young patients with completed stroke.

In a consecutive series of 11 young patients with clinical evidence of cerebral infarction, platelet function and plasma lipid levels were examined. The results show that increased platelet aggregability characterizes the patient group as a whole. Hyperlipidemia was frequently found, and the number of heavy smokers was high. It is suggested that all younger patients with cerebrovascular disease are examined with regard to these presumed risk factors.

Adenosine Diphosphate↗
PubMed1977

Low cerebral blood flow in hypotensive perinatal distress.

Hypoxic brain injury is the most important neurological problem in the neonatal period and accounts for more neurological deficits in children than any other lesion. The neurological deficits are notably mental retardation, epilepsy and cerebral palsy. The pathogenesis has hitherto been poorly understood. Arterial hypoxia has been taken as the obvious mechanism but this does not fully explain the patho-anatomical findings. In the present investigation we have examined the arterial blood pressure and the cerebral blood flow in eight infants a few hours after birth. The 133Xe clearance technique was used for the cerebral blood flow measurements. The study confirmed that perinatal distress may be associated with low arterial blood pressure, and it was shown that cerebral blood flow is very low, 20 ml/100 g/min or less, in hypotensive perinatal distress. It is concluded that cerebral ischaemia plays a crucial role in the development of perinatal hypoxic brain injury.

Asphyxia Neonatorum↗
PubMed1976

Progressive external ophthalmoplegia. Evidence for a generalised mitochondrial disease with a defect in pyruvate metabolism.

Muscle biopsies from four patients with chronic progressive external ophthalmoplegia and pigmentary retinopathy with symptoms and signs from other organs were studied by means of light and electron microscopy. Examination revealed a marked proliferation of abnormal mitochondria with a degeneration of both muscle and nerve tissue. Blood levels of lactate and pyruvate were measured and abnormal values of these metabolites were found in the three patients with the most pronounced ultrastructural changes. On the basis of these findings it is suggested that there is a biochemical defect in pyruvate-lactate metabolism which could be responsible for the marked proliferation of the abnormal mitochondria.

Adolescent↗
PubMed1972

[Brain death].

Explore the source record for details and available documents.

Brain Death↗
PubMedDate not supplied

T1, T2, and concentrations of brain metabolites in neonates and adolescents estimated with H-1 MR spectroscopy.

The protein and lipid content of the human brain increases dramatically from infancy to adolescence. The authors investigated whether this change influences the relaxation behavior of metabolites measurable with hydrogen-1 magnetic resonance (MR) spectroscopy. H-1 MR spectroscopy was performed in eight neonates and eight adolescents at 1.5 T with STEAM (stimulated-echo acquisition mode) sequences. Five spectra were obtained in each volume of interest with different TE and TR values. T1 and T2 were subsequently calculated. T1 and T2 for inositols, choline-containing compounds (Cho), phosphocreatine plus creatine (PCr + Cr), and N-acetylaspartate (NAA) did not differ significantly between the two subject groups. Metabolite concentrations were estimated by using the fully relaxed water signal as an internal standard. Mean estimated concentrations of NAA and PCr + Cr were higher in the adolescent group, whereas the concentration of Cho was lower. The concentration of inositols was similar in the two groups.

Adolescent↗
PubMedDate not supplied

Metabolite concentrations in the developing brain estimated with proton MR spectroscopy.

The purpose of the present study was to estimate absolute concentrations and relaxation time constants of metabolites that were detectable with proton magnetic resonance (MR) spectroscopy in the healthy preterm, term, and infant brain. Five MR spectra were recorded for each infant by using STEAM (stimulated-echo acquisition mode) sequences with different TEs and TRs. Water was used as an internal standard. The T1 of choline-containing compounds (Cho) and the T1 of phosphocreatine plus creatine (PCr+Cr) decreased. The T2 of the N-acetyl-L-aspartate (NAA) resonance increased, probably because of a relatively larger signal overlap with glutamate in the most immature brains. The concentration of NAA almost doubled, whereas the Cho concentration showed only a nonsignificant tendency to decrease; therefore, the well-known increase in the ratio of NAA to Cho appears to be due mostly to an increase in NAA concentration. The concentration of PCr+Cr increased rapidly and reached adolescent values at approximately 4 months of age.

Aspartic Acid↗